[Ti] FireWire Port Problem

[Dave Friesen]

While the actual cause is still up for debate the solution I sent to this
list is a special cable from FW Depot which is a 6 pin cable which omits the
two power wires. It prevents any power feedback but also prevents a FW bus
powered device. Which apparently is ok as the port issue (hopefully) is only
causes by FW devices that are externally powered.

On 9/30/03 1:44 PM, "b" <fl1pper at earthlink.net> wrote:

> Tarik paused, thought it over, and spoke thusly:

> After some research, I find it is, indeed, arcing. Power in the
> cable, or device, that gets accidentally shunted over to the data
> line (s) in the cable or device. This fries the PHY box that is on
> the host firewire port. (It is responsible for sending power out of
> the 'extra' wires in the ports that also supply power in addition to
> data.
> 
> Usually a cable (that either twists, or is mounted backwards (hard
> but possible, apparently), is the culprit. The advice, in terms of
> prevention, is to use high quality cables, change them often
> (monthly?), be careful on plugging-in, don't let the cable 'twist'
> anywhere near the connector ends, and if possible, use 3-way (
> External Power/Off/Bus Power) devices.
> 
> A short, high-quality cable, that might have developed an arc due to
> subtle 'twists', over time, probably fried the port on my Powerbook.
> If Apple had implemented the anti-Static/anti-Power over/under
> circuit on the port, earlier, it all would have been avoided.
> 
> As for me, given current dire straits, I may just wait ( quite a
> while ) for an UltraWide SCSI PC card, and go that route (skipping
> FireWire/USB and the slow drives, altogether). I hope such a thing
> exists. In the meantime, I am all the way out of business.
> 
> ~flipper